In manufacturing industrial products such as electronic components including a semiconductor component and a printed wiring board, high definition patterning is carried out by patterning an etching mask on a substrate and etching out regions other than a region of the etching mask (for example, Patent Documents 1 and 2).
The etching mask is formed by, for example, after a photosensitive layer is formed of a photosensitive material on a surface of a metal layer, carrying out exposure to form an exposed portion and a non-exposed portion in the photosensitive layer and carrying out development using difference in solubility in the developer between the exposed portion and the non-exposed portion.
However, in recent years, as electronic components become finer, higher definition patterning is required to be realized, and high definition patterning of the etching mask is required accordingly.